Negative pressure wound treatment apparatuses and methods with integrated electronics

ABSTRACT

Disclosed embodiments relate to apparatuses and methods for wound treatment. A wound dressing apparatus can comprises a wound contact layer, at least one absorbent layer, an electronics unit comprising a negative pressure source unit, and a cover layer. The electronics unit can comprise a plurality of sensors positioned on a printed circuit board and an inlet protection mechanism of the negative pressure source unit comprises a first recess in fluid communication with a first sensor and the outlet or exhaust mechanism negative pressure source unit comprises a second recess in fluid communication with a second sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application of InternationalPatent Application No. PCT/EP2018/074694, filed Sep. 13, 2018, whichclaims priority to U.S. Provisional Patent Application No. 62/558,264,filed on Sep. 13, 2017, which is hereby incorporated by reference in itsentirety and made part of this disclosure.

BACKGROUND Technical Field

Embodiments described herein relate to apparatuses, systems, and methodsthe treatment of wounds, for example using dressings in combination withnegative pressure wound therapy.

Description of the Related Art

The treatment of open or chronic wounds that are too large tospontaneously close or otherwise fail to heal by means of applyingnegative pressure to the site of the wound is well known in the art.Negative pressure wound therapy (NPWT) systems currently known in theart commonly involve placing a cover that is impermeable orsemi-permeable to fluids over the wound, using various means to seal thecover to the tissue of the patient surrounding the wound, and connectinga source of negative pressure (such as a vacuum pump) to the cover in amanner so that negative pressure is created and maintained under thecover. It is believed that such negative pressures promote wound healingby facilitating the formation of granulation tissue at the wound siteand assisting the body's normal inflammatory process whilesimultaneously removing excess fluid, which may contain adversecytokines and/or bacteria. However, further improvements in NPWT areneeded to fully realize the benefits of treatment.

Many different types of wound dressings are known for aiding in NPWTsystems. These different types of wound dressings include many differenttypes of materials and layers, for example, gauze, pads, foam pads ormulti-layer wound dressings. One example of a multi-layer wound dressingis the PICO dressing, available from Smith & Nephew, which includes asuperabsorbent layer beneath a backing layer to provide a canister-lesssystem for treating a wound with NPWT. The wound dressing may be sealedto a suction port providing connection to a length of tubing, which maybe used to pump fluid out of the dressing and/or to transmit negativepressure from a pump to the wound dressing.

Prior art dressings for use in negative pressure such as those describedabove have included a negative pressure source located in a remotelocation from the wound dressing. Negative pressure sources locatedremote from the wound dressing have to be held by or attached to theuser or other pump support mechanism. Additionally, a tubing orconnector is required to connect the remote negative pressure source tothe wound dressing. The remote pump and tubing can be cumbersome anddifficult to hide in or attach to patient clothing. Depending on thelocation of the wound dressing, it can be difficult to comfortably andconveniently position the remote pump and tubing. When used, woundexudate may soak into the dressing, and the moisture from the wound hasmade it difficult to incorporate electronic components into thedressing.

SUMMARY

Embodiments of the present disclosure relate to apparatuses and methodsfor wound treatment. Some of the wound treatment apparatuses describedherein comprise a negative pressure source or a pump system forproviding negative pressure to a wound. Wound treatment apparatuses mayalso comprise wound dressings that may be used in combination with thenegative pressure sources and pump assemblies described herein. In someembodiments, a negative pressure source is incorporated into a wounddressing apparatus so that the wound dressing and the negative pressuresource are part of an integral or integrated wound dressing structurethat applies the wound dressing and the negative pressure sourcesimultaneously to a patient's wound. The negative pressure source and/orelectronic components may be positioned between a wound contact layerand a cover layer of the wound dressing. An electronics assembly can beincorporated into the absorbent material of the dressing to preventpooling of wound exudate and maintain conformability of the dressing.These and other embodiments as described herein are directed toovercoming particular challenges involved with incorporating a negativepressure source and/or electronic components into a wound dressing.

According to one embodiment, a wound dressing apparatus can comprise awound contact layer comprising a proximal wound-facing face and a distalface, wherein the proximal wound-facing face is configured to bepositioned in contact with a wound, at least one absorbent layer overthe wound contact layer, an electronics unit comprising a negativepressure source unit comprising a negative pressure source, inletprotection mechanism, and an outlet or exhaust mechanism, a plurality ofsensors positioned on a printed circuit board, wherein the inletprotection mechanism comprises a first recess configured to be in fluidcommunication with a first sensor on the printed circuit board and theoutlet or exhaust mechanism comprises a second recess configured to bein fluid communication with a second sensor on the printed circuitboard, and wherein the at least one absorbent layer is configured to bein fluid communication with the electronics unit; and a cover layerconfigured to cover and form a seal over the wound contact layer, the atleast one absorbent layer, and the electronics unit.

The wound dressing apparatus of the preceding paragraph or in otherembodiments can include one or more of the following features. The firstrecess can be positioned over the first sensor, wherein the perimeter ofthe first recess comprises a first gasket configured to seal theperimeter of the first recess in the inlet protection mechanism to theprinted circuit board surrounding the first sensor. The second recesscan be positioned over the second sensor, wherein the perimeter of thesecond recess comprises a second gasket configured to seal the perimeterof the second recess of the outlet or exhaust mechanism to the printedcircuit board surrounding the second sensor. The outlet or exhaustmechanism can comprises at least one vent aperture and the printedcircuit board can comprise at least one vent hole in the printed circuitboard, wherein the at least one vent aperture of the outlet or exhaustmechanism is configured to be in fluid communication with the at leastone vent hole of the printed circuit board. The second gasket cancomprise an aperture configured to provide fluid communication between avent hole of the at least one vent hole of the printed circuit board anda vent aperture of the at least one vent aperture of the outlet orexhaust mechanism through the second gasket. The at least one ventaperture of the outlet or exhaust mechanism can comprise anantibacterial membrane and/or a non-return valve. The cover layer cancomprise an aperture over the at least one vent aperture. Theelectronics unit can comprise one or more power sources. The at leastone absorbent layer can comprise one or more recesses configured toreceive the electronics unit. The wound dressing can further comprisinga transmission layer comprising a proximal wound-facing face and adistal face, the transmission layer can be positioned over the distalface of the wound contact layer. The at least one absorbent layer cancomprise a first absorbent layer comprising a proximal wound-facing faceand a distal face, the first absorbent layer can be positioned on thedistal face of the transmission layer and a second absorbent comprisinga proximal wound-facing face and a distal face, the second absorbentlayer can be positioned on the distal face of the first absorbent layer.The wound dressing can further comprising an overlay layer comprising aproximal wound-facing face and a distal face, the overlay layer can bepositioned over the distal face of the second absorbent layer, whereinthe overlay layer comprises a larger perimeter than a perimeter of thetransmission layer and the first and second absorbent layer. Theelectronic unit can comprise a switch. The electronic unit can comprisea light or LED indicator.

Any of the features, components, or details of any of the arrangementsor embodiments disclosed in this application, including withoutlimitation any of the pump embodiments and any of the negative pressurewound therapy embodiments disclosed below, are interchangeablycombinable with any other features, components, or details of any of thearrangements or embodiments disclosed herein to form new arrangementsand embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-1C illustrates a wound dressing apparatus incorporating the pumpand/or other electronic components within the wound dressing and offsetfrom the absorbent layer;

FIG. 2A illustrate an embodiment of the electronics unit;

FIGS. 2B-2C illustrate embodiments of the pump and electronics unit;

FIG. 3 illustrates an embodiment of a wound dressing incorporating anelectronics unit within the dressing;

FIGS. 4A-4C illustrate an embodiment of a wound dressing incorporatingan electronics unit in the absorbent layer;

FIGS. 5A-5B illustrate an embodiment of a wound dressing incorporatingan electronics unit;

FIG. 6 illustrates an embodiment of wound dressing layers incorporatingthe electronic components within the wound dressing;

FIGS. 7A-7C illustrates embodiments of individual layers of a wounddressing;

FIGS. 8A-8F illustrates embodiments of layers of the wound dressingincorporating an electronics assembly within the dressing;

FIG. 9 illustrates a cross sectional layout of the material layers ofthe wound dressing incorporating an electronics assembly within thedressing

FIGS. 10A-10C and 11A-11B illustrate embodiments of components of anelectronics unit including a printed circuit board, the negativepressure source, and one or more power sources;

FIG. 12 illustrates an embodiment of a pump assembly incorporatingadhesive gaskets;

FIG. 13 illustrates an embodiment of a pump inlet protection mechanism;and

FIG. 14 illustrates an embodiment of a pump outlet mechanism.

DETAILED DESCRIPTION

Embodiments disclosed herein relate to apparatuses and methods oftreating a wound with reduced pressure, including a source of negativepressure and wound dressing components and apparatuses. The apparatusesand components comprising the wound overlay and packing materials, ifany, are sometimes collectively referred to herein as dressings.

It will be appreciated that throughout this specification reference ismade to a wound. It is to be understood that the term wound is to bebroadly construed and encompasses open and closed wounds in which skinis torn, cut or punctured or where trauma causes a contusion, or anyother superficial or other conditions or imperfections on the skin of apatient or otherwise that benefit from reduced pressure treatment. Awound is thus broadly defined as any damaged region of tissue wherefluid may or may not be produced. Examples of such wounds include, butare not limited to, abdominal wounds or other large or incisionalwounds, either as a result of surgery, trauma, sterniotomies,fasciotomies, or other conditions, dehisced wounds, acute wounds,chronic wounds, subacute and dehisced wounds, traumatic wounds, flapsand skin grafts, lacerations, abrasions, contusions, burns, diabeticulcers, pressure ulcers, stoma, surgical wounds, trauma and venousulcers or the like.

It will be understood that embodiments of the present disclosure aregenerally applicable to use in topical negative pressure (“TNP”) therapysystems. Briefly, negative pressure wound therapy assists in the closureand healing of many forms of “hard to heal” wounds by reducing tissueoedema; encouraging blood flow and granular tissue formation; removingexcess exudate and may reduce bacterial load (and thus infection risk).In addition, the therapy allows for less disturbance of a wound leadingto more rapid healing. TNP therapy systems may also assist on thehealing of surgically closed wounds by removing fluid and by helping tostabilize the tissue in the apposed position of closure. A furtherbeneficial use of TNP therapy can be found in grafts and flaps whereremoval of excess fluid is important and close proximity of the graft totissue is required in order to ensure tissue viability.

As is used herein, reduced or negative pressure levels, such as —X mmHg,represent pressure levels relative to normal ambient atmosphericpressure, which can correspond to 760 mmHg (or 1 atm, 29.93 inHg,101.325 kPa, 14.696 psi, etc.). Accordingly, a negative pressure valueof −X mmHg reflects absolute pressure that is X mmHg below 760 mmHg or,in other words, an absolute pressure of (760−X) mmHg. In addition,negative pressure that is “less” or “smaller” than X mmHg corresponds topressure that is closer to atmospheric pressure (e.g., −40 mmHg is lessthan −60 mmHg). Negative pressure that is “more” or “greater” than −XmmHg corresponds to pressure that is further from atmospheric pressure(e.g., −80 mmHg is more than −60 mmHg). In some embodiments, localambient atmospheric pressure is used as a reference point, and suchlocal atmospheric pressure may not necessarily be, for example, 760mmHg.

The negative pressure range for some embodiments of the presentdisclosure can be approximately −80 mmHg, or between about −20 mmHg and−200 mmHg Note that these pressures are relative to normal ambientatmospheric pressure, which can be 760 mmHg. Thus, −200 mmHg would beabout 560 mmHg in practical terms. In some embodiments, the pressurerange can be between about −40 mmHg and −150 mmHg. Alternatively apressure range of up to −75 mmHg, up to −80 mmHg or over −80 mmHg can beused. Also in other embodiments a pressure range of below −75 mmHg canbe used. Alternatively, a pressure range of over approximately −100mmHg, or even −150 mmHg, can be supplied by the negative pressureapparatus.

In some embodiments of wound closure devices described herein, increasedwound contraction can lead to increased tissue expansion in thesurrounding wound tissue. This effect may be increased by varying theforce applied to the tissue, for example by varying the negativepressure applied to the wound over time, possibly in conjunction withincreased tensile forces applied to the wound via embodiments of thewound closure devices. In some embodiments, negative pressure may bevaried over time for example using a sinusoidal wave, square wave,and/or in synchronization with one or more patient physiological indices(e.g., heartbeat). Examples of such applications where additionaldisclosure relating to the preceding may be found include U.S. Pat. No.8,235,955, titled “Wound treatment apparatus and method,” issued on Aug.7, 2012; and U.S. Pat. No. 7,753,894, titled “Wound cleansing apparatuswith stress,” issued Jul. 13, 2010. The disclosures of both of thesepatents are hereby incorporated by reference in their entirety.

International Application PCT/GB2012/000587, titled “WOUND DRESSING ANDMETHOD OF TREATMENT” and filed on Jul. 12, 2012, and published as WO2013/007973 A2 on Jan. 17, 2013, is an application, hereby incorporatedby reference in its entirety, that is directed to embodiments, methodsof manufacture, and wound dressing components and wound treatmentapparatuses that may be used in combination or in addition to theembodiments described herein. Additionally, embodiments of the wounddressings, wound treatment apparatuses and methods described herein mayalso be used in combination or in addition to those described inInternational Application No. PCT/IB2013/001469, filed May 22, 2013,titled “APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY,”published as WO 2013/175306 on Nov. 28, 2013, U.S. patent applicationSer. No. 14/418,874, filed Jan. 30, 2015, published as U.S. PublicationNo. 2015/0216733, published Aug. 6, 2015, titled “WOUND DRESSING ANDMETHOD OF TREATMENT,” U.S. patent application Ser. No. 14/418,908, filedJan. 30, 2015, published as U.S. Publication No. 2015/0190286, publishedJul. 9, 2015, titled “WOUND DRESSING AND METHOD OF TREATMENT,” U.S.patent application Ser. No. 14/658,068, filed Mar. 13, 2015, U.S.Application No. 2015/0182677, published Jul. 2, 2015, titled “WOUNDDRESSING AND METHOD OF TREATMENT,” the disclosures of which are herebyincorporated by reference in their entireties. Embodiments of the wounddressings, wound treatment apparatuses and methods described herein mayalso be used in combination or in addition to those described in U.S.patent application Ser. No. 13/092,042, filed Apr. 21 2011, published asU.S. 2011/0282309, titled “WOUND DRESSING AND METHOD OF USE,” and whichis hereby incorporated by reference in its entirety, including furtherdetails relating to embodiments of wound dressings, the wound dressingcomponents and principles, and the materials used for the wounddressings.

Embodiments of the wound dressings, wound treatment apparatuses andmethods described herein relating to wound dressings with electronicsincorporated into the dressing may also be used in combination or inaddition to those described in International ApplicationPCT/EP2017/055225, filed Mar. 6, 2017, titled “WOUND TREATMENTAPPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTOWOUND DRESSING,” and which is hereby incorporated by reference in itsentirety, including further details relating to embodiments of wounddressings, the wound dressing components and principles, and thematerials used for the wound dressings.

In some embodiments, a source of negative pressure (such as a pump) andsome or all other components of the TNP system, such as power source(s),sensor(s), connector(s), user interface component(s) (such as button(s),switch(es), speaker(s), screen(s), etc.) and the like, can be integralwith the wound dressing. The wound dressing can include various materiallayers described here and described in further detail in InternationalApplication No. PCT/EP2017/055225, filed Mar. 6, 2017, entitled WOUNDTREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCEINTEGRATED INTO WOUND DRESSING. The material layers can include a woundcontact layer, one or more absorbent layers, one or more spacer ortransmission layers, and a backing layer or cover layer covering the oneor more absorbent and spacer or transmission layers. The wound dressingcan be placed over a wound and sealed to the wound with the pump and/orother electronic components contained under the cover layer within thewound dressing. In some embodiments, the dressing can be provided as asingle article with all wound dressing elements (including the pump)pre-attached and integrated into a single unit. In some embodiments, aperiphery of the wound contact layer can be attached to the periphery ofthe cover layer enclosing all wound dressing elements as illustrated inFIG. 1A-1C.

In some embodiments, the pump and/or other electronic components can beconfigured to be positioned adjacent to or next to the absorbent and/ortransmission layers so that the pump and/or other electronic componentsare still part of a single article to be applied to a patient. In someembodiments, with the pump and/or other electronics positioned away fromthe wound site. FIGS. 1A-1C illustrates a wound dressing incorporatingthe source of negative pressure and/or other electronic componentswithin the wound dressing. FIGS. 1A-1C illustrates a wound dressing 100with the pump and/or other electronics positioned away from the woundsite. The wound dressing can include an electronics area 161 and anabsorbent area 160. The dressing can comprise a wound contact layer 110(not shown in FIGS. 1A-1B) and a moisture vapor permeable film or coverlayer 113 positioned above the contact layer and other layers of thedressing. The wound dressing layers and components of the electronicsarea as well as the absorbent area can be covered by one continuouscover layer 113 as shown in FIGS. 1A-1C.

The dressing can comprise a wound contact layer 110, a transmissionlayer 111, an absorbent layer 112, a moisture vapor permeable film orcover layer 113, 113 positioned above the wound contact layer,transmission layer, absorbent layer, or other layers of the dressing.The wound contact layer can be configured to be in contact with thewound. The wound contact layer can include an adhesive on the patientfacing side for securing the dressing to the surrounding skin or on thetop side for securing the wound contact layer to a cover layer or otherlayer of the dressing. In operation, the wound contact layer can beconfigured to provide unidirectional flow so as to facilitate removal ofexudate from the wound while blocking or substantially preventingexudate from returning to the wound.

The wound contact layer 110 can be a polyurethane layer or polyethylenelayer or other flexible layer which is perforated, for example via a hotpin process, laser ablation process, ultrasound process or in some otherway or otherwise made permeable to liquid and gas. The wound contactlayer 110 has a lower surface and an upper surface. The perforationspreferably comprise through holes in the wound contact layer 110 whichenable fluid to flow through the layer 110. The wound contact layer 110helps prevent tissue ingrowth into the other material of the wounddressing. Preferably, the perforations are small enough to meet thisrequirement while still allowing fluid to flow therethrough. Forexample, perforations formed as slits or holes having a size rangingfrom 0.025 mm to 1.2 mm are considered small enough to help preventtissue ingrowth into the wound dressing while allowing wound exudate toflow into the dressing. In some configurations, the wound contact layer110 may help maintain the integrity of the entire dressing 100 whilealso creating an air tight seal around the absorbent pad in order tomaintain negative pressure at the wound.

Some embodiments of the wound contact layer 110 may also act as acarrier for an optional lower and upper adhesive layer (not shown). Forexample, a lower pressure sensitive adhesive may be provided on thelower surface of the wound dressing 100 whilst an upper pressuresensitive adhesive layer may be provided on the upper surface of thewound contact layer. The pressure sensitive adhesive, which may be asilicone, hot melt, hydrocolloid or acrylic based adhesive or other suchadhesives, may be formed on both sides or optionally on a selected oneor none of the sides of the wound contact layer. When a lower pressuresensitive adhesive layer is utilized it may be helpful to adhere thewound dressing 100 to the skin around a wound site. In some embodiments,the wound contact layer may comprise perforated polyurethane film. Thelower surface of the film may be provided with a silicone pressuresensitive adhesive and the upper surface may be provided with an acrylicpressure sensitive adhesive, which may help the dressing maintain itsintegrity. In some embodiments, a polyurethane film layer may beprovided with an adhesive layer on both its upper surface and lowersurface, and all three layers may be perforated together.

A layer 111 of porous or transmission material can be located above thewound contact layer 110. As used herein, the terms porous material,spacer, and/or transmission layer can be used interchangeably to referto the layer of material in the dressing configured to distributenegative pressure throughout the wound area. This porous layer, ortransmission layer, 111 allows transmission of fluid including liquidand gas away from a wound site into upper layers of the wound dressing.In particular, the transmission layer 111 preferably ensures that anopen air channel can be maintained to communicate negative pressure overthe wound area even when the absorbent layer has absorbed substantialamounts of exudates. The layer 111 should preferably remain open underthe typical pressures that will be applied during negative pressurewound therapy as described above, so that the whole wound site sees anequalized negative pressure. The layer 111 may be formed of a materialhaving a three dimensional structure. For example, a knitted or wovenspacer fabric (for example Baltex 7970 weft knitted polyester) or anon-woven fabric could be used.

The transmission layer assists in distributing negative pressure overthe wound site and facilitating transport of wound exudate and fluidsinto the wound dressing. In some embodiments, the transmission layer canbe formed at least partially from a three dimensional (3D) fabric.

In some embodiments, the transmission layer 111 comprises a 3D polyesterspacer fabric layer including a top layer (that is to say, a layerdistal from the wound-bed in use) which is a 84/144 textured polyester,and a bottom layer (that is to say, a layer which lies proximate to thewound bed in use) which is a 10 denier flat polyester and a third layerformed sandwiched between these two layers which is a region defined bya knitted polyester viscose, cellulose or the like mono filament fiber.Other materials and other linear mass densities of fiber could of coursebe used.

Whilst reference is made throughout this disclosure to a monofilamentfiber it will be appreciated that a multistrand alternative could ofcourse be utilized. The top spacer fabric thus has more filaments in ayarn used to form it than the number of filaments making up the yarnused to form the bottom spacer fabric layer.

This differential between filament counts in the spaced apart layershelps control moisture flow across the transmission layer. Particularly,by having a filament count greater in the top layer, that is to say, thetop layer is made from a yarn having more filaments than the yarn usedin the bottom layer, liquid tends to be wicked along the top layer morethan the bottom layer. In use, this differential tends to draw liquidaway from the wound bed and into a central region of the dressing wherethe absorbent layer 112 helps lock the liquid away or itself wicks theliquid onwards towards the cover layer 113 where it can be transpired.

Preferably, to improve the liquid flow across the transmission layer 111(that is to say perpendicular to the channel region formed between thetop and bottom spacer layers), the 3D fabric may be treated with a drycleaning agent (such as, but not limited to, Perchloro Ethylene) to helpremove any manufacturing products such as mineral oils, fats or waxesused previously which might interfere with the hydrophilic capabilitiesof the transmission layer. In some embodiments, an additionalmanufacturing step can subsequently be carried in which the 3D spacerfabric is washed in a hydrophilic agent (such as, but not limited to,Feran Ice 30 g/l available from the Rudolph Group). This process stephelps ensure that the surface tension on the materials is so low thatliquid such as water can enter the fabric as soon as it contacts the 3Dknit fabric. This also aids in controlling the flow of the liquid insultcomponent of any exudates.

Further, an absorbent layer (such as layer 112) for absorbing andretaining exudate aspirated from the wound can be utilized. In someembodiments, a superabsorbent material can be used in the absorbentlayer 112. In some embodiments, the absorbent includes a shaped form ofa superabsorber layer.

A layer 112 of absorbent material is provided above the transmissionlayer 111. The absorbent material, which comprise a foam or non-wovennatural or synthetic material, and which may optionally comprise asuper-absorbent material, forms a reservoir for fluid, particularlyliquid, removed from the wound site. In some embodiments, the layer 111may also aid in drawing fluids towards the cover layer 113.

The material of the absorbent layer 112 may also prevent liquidcollected in the wound dressing from flowing freely within the dressing,and preferably acts so as to contain any liquid collected within thedressing. The absorbent layer 112 also helps distribute fluid throughoutthe layer via a wicking action so that fluid is drawn from the woundsite and stored throughout the absorbent layer. This helps preventagglomeration in areas of the absorbent layer. The capacity of theabsorbent material must be sufficient to manage the exudates flow rateof a wound when negative pressure is applied. Since in use the absorbentlayer experiences negative pressures the material of the absorbent layeris chosen to absorb liquid under such circumstances. A number ofmaterials exist that are able to absorb liquid when under negativepressure, for example superabsorber material. The absorbent layer 112may typically be manufactured from ALLEVYN™ foam, Freudenberg 114-224-4or Chem-Posite™ 11C-450. In some embodiments, the absorbent layer 112may comprise a composite comprising superabsorbent powder, fibrousmaterial such as cellulose, and bonding fibers. In a preferredembodiment, the composite is an airlaid, thermally-bonded composite.

In some embodiments, the absorbent layer 112 is a layer of non-wovencellulose fibers having super-absorbent material in the form of dryparticles dispersed throughout. Use of the cellulose fibers introducesfast wicking elements which help quickly and evenly distribute liquidtaken up by the dressing. The juxtaposition of multiple strand-likefibers leads to strong capillary action in the fibrous pad which helpsdistribute liquid. In this way, the super-absorbent material isefficiently supplied with liquid. The wicking action also assists inbringing liquid into contact with the upper cover layer to aid increasetranspiration rates of the dressing.

The wound dressing layers of the electronics area and the absorbentlayer can be covered by one continuous cover layer or backing layer 113.As used herein, the terms cover layer and/or backing layer can be usedinterchangeably to refer to the layer of material in the dressingconfigured to cover the underlying dressing layers and seal to the woundcontact layer and/or the skin surrounding the wound. In someembodiments, the cover layer can include a moisture vapor permeablematerial that prevents liquid exudate removed from the wound and otherliquids from passing through, while allowing gases through.

The cover layer 113 is preferably gas impermeable, but moisture vaporpermeable, and can extend across the width of the wound dressing 100.The cover layer 113, which may for example be a polyurethane film (forexample, Elastollan SP9109) having a pressure sensitive adhesive on oneside, is impermeable to gas and this layer thus operates to cover thewound and to seal a wound cavity over which the wound dressing isplaced. In this way an effective chamber is made between the cover layer113 and a wound site where a negative pressure can be established. Thecover layer 113 is preferably sealed to the wound contact layer 110 in aborder region around the circumference of the dressing, ensuring that noair is drawn in through the border area, for example via adhesive orwelding techniques. The cover layer 113 protects the wound from externalbacterial contamination (bacterial barrier) and allows liquid from woundexudates to be transferred through the layer and evaporated from thefilm outer surface. The cover layer 113 preferably comprises two layers;a polyurethane film and an adhesive pattern spread onto the film. Thepolyurethane film is preferably moisture vapor permeable and may bemanufactured from a material that has an increased water transmissionrate when wet. In some embodiments, the moisture vapor permeability ofthe cover layer increases when the cover layer becomes wet. The moisturevapor permeability of the wet cover layer may be up to about ten timesmore than the moisture vapor permeability of the dry cover layer.

The electronics area 161 can include a source of negative pressure (suchas a pump) and some or all other components of the TNP system, such aspower source(s), sensor(s), connector(s), user interface component(s)(such as button(s), switch(es), speaker(s), screen(s), etc.) and thelike, that can be integral with the wound dressing. For example, theelectronics area 161 can include a button or switch 114 as shown inFIGS. 1A-1B. The button or switch 114 can be used for operating the pump(e.g., turning the pump on/off).

The absorbent area 160 can include an absorbent material 112 and can bepositioned over the wound site. The electronics area 161 can bepositioned away from the wound site, such as by being located off to theside from the absorbent area 160. The electronics area 161 can bepositioned adjacent to and in fluid communication with the absorbentarea 160 as shown in FIGS. 1A-1C. In some embodiments, each of theelectronics area 161 and absorbent area 160 may be rectangular in shapeand positioned adjacent to one another. In some embodiments, theelectronics unit can be within absorbent material in the electronicsarea 160 of the dressing as described herein. As illustrated in FIG. 1C,the electronics unit can be positioned within the absorbent material butoff to the side of the absorbent area.

In some embodiments, additional layers of dressing material can beincluded in the electronics area 161, the absorbent area 160, or bothareas. In some embodiments, the dressing can comprise one or moretransmission layers and/or one or more absorbent layer positioned abovethe wound contact layer 110 and below the cover layer 113 of thedressing.

In some embodiments, the electronics area 161 of the dressing cancomprise electronic components 150. In some embodiments, the electronicsarea 161 of the dressing can comprise a plurality of layers oftransmission material and/or absorbent material and electroniccomponents 150 can be embedded within the plurality of layers oftransmission material and/or absorbent material. The layers oftransmission or absorbent material can have recesses or cut outs toembed the electronic components 150 within whilst providing structure toprevent collapse. The electronic components 150 can include a pump,power source, controller, and/or an electronics package.

A pump exhaust can be provided to exhaust air from the pump to theoutside of the dressing. The pump exhaust can be in communication withthe electronics area 161 and the outside of the dressing.

As used herein the upper layer, top layer, or layer above refers to alayer furthest from the surface of the skin or wound while the dressingis in use and positioned over the wound. Accordingly, the lower surface,lower layer, bottom layer, or layer below refers to the layer that isclosest to the surface of the skin or wound while the dressing is in useand positioned over the wound. Additionally, the layers can have aproximal wound-facing face referring to a side or face of the layerclosest to the skin or wound and a distal face referring to a side orface of the layer furthest from the skin or wound.

FIG. 1A-1C illustrates a wound dressing apparatus incorporating the pumpand/or other electronic components within the wound dressing and offsetfrom the absorbent layer. In some embodiments, as shown in FIG. 1C, theabsorbent area 160 comprises a transmission layer 111 positioned abovethe wound contact layer 110. An absorbent layer 112 can be providedabove the transmission layer 111. In some embodiments, the electronicsarea 161 can include an electronics unit (shown in FIGS. 2A-2C). In someembodiments, the electronics unit is provided directly over the woundcontact layer. In other embodiments, the electronics unit can be placedabove a layer of wicking material, absorbent material, or transmissionmaterial that sits above the wound contact layer 110 of the dressing.For example, as shown in FIG. 1C, the electronics unit 150 may bepositioned over the transmission layer 111. In some embodiments, thetransmission layer 111 can be a single layer of material extending belowthe electronics unit 150 and the absorbent material 112. Thus, in someembodiments, the transmission layer 111 extends continuously through theabsorbent area 160 and the electronics area 161. In alternativeembodiments, the transmission layer below the electronics unit can be adifferent transmission layer than the transmission layer below theabsorbent material 112. The transmission layer 111, absorbent material112, and electronics unit 150 can be covered with a cover layer 113 thatseals to a perimeter of the wound contact layer 110 as shown in FIGS.1A-1C.

The electronics area 161 can include an electronics unit 150 positionedbelow the cover layer 113 of the dressing. In some embodiments, theelectronics unit can be surrounded by a material to enclose orencapsulate a negative pressure source and electronics components bysurrounding the electronics. In some embodiments, this material can be acasing. In some embodiments, the electronics unit can be encapsulated orsurrounded by a protective coating, for example, a hydrophobic coatingas described herein. The electronics unit can be in contact with thedressing layers in the absorbent area 160 and covered by the cover layer113. As used herein, the electronics unit includes a lower or woundfacing surface that is closest to the wound and an opposite, uppersurface, furthest from the wound when the wound dressing is placed overa wound.

FIG. 2A illustrate an embodiment of the electronics unit 267. FIG. 2Aillustrates an embodiment of a pump and electronics unit 267 that can beincorporated into a wound dressing. The electronics unit 267 of FIG. 2Ais shown without an electronics casing or other dressing material. FIGS.2B-2C illustrate embodiments of the pump and electronics unit 267. FIG.2B illustrates the top view of the electronics unit. FIG. 2C illustratesa bottom or wound facing surface of the electronics unit.

As illustrated in FIG. 2A-2B, the electronics unit 267 can includesingle button 265 on the upper surface of the unit. The single button265 can be used as an on/off button or switch to stop and startoperation of the pump and/or electronic components. The switch 265 canbe a dome type switch configured to sit on the top of the pump. Becausethe switch is situated within the dressing the cover layer can be easilysealed around or over the switch. In some embodiments, the cover layercan have an opening or hole positioned above the switch. The cover layercan be sealed to the outer perimeter of the switch 265 to maintainnegative pressure under the wound cover. The switch can be placed on anysurface of the electronics unit and can be in electrical connection withthe pump.

The electronics unit 267 can also include one or more vents or exhausts264 for the pump outlet. However, the vent or exhaust 264 is positionedat the outlet of the pump and extending to the upper surface of theelectronics unit. As shown in FIG. 2A, the pump outlet exhaust 264 isattached to the outlet of the pump and provides communication with thetop surface of the dressing. In some embodiments, the exhaust 264 can beattached to the outlet end of the pump and can extend out from the pumpat a 90-degree angle from the pump orientation to communicate with thetop surface of the dressing. The exhaust 264 can include anantibacterial membrane and a non-return valve. The exhausted air fromthe pump can pass through the pump outlet and exhaust mechanism 274. Insome embodiments, the cover layer 113 can include apertures or holespositioned above the exhaust vents 264 and/or membrane. The cover layer113 can be sealed to the outer perimeter of the exhaust vents 264 tomaintain negative pressure under the wound cover 113. In someembodiments, the exhausted air can be exhausted through the gaspermeable material or moisture vapor permeable material of the coverlayer. In some embodiments, the cover layer does not need to containapertures or holes over the exhaust and the exhausted air is expelledthrough the cover layer. In some embodiments, the pump outlet mechanism274 can be a custom part formed to fit around the pump as shown in FIG.2A-2C. The electronic unit 267 can include a pump inlet protectionmechanism 280 (shown in FIG. 2C) positioned on the portion of theelectronic unit closest to the absorbent area and aligned with the inletof the pump 272. The pump inlet protection mechanism is positionedbetween the pump inlet and the absorbent area or absorbent layer of thedressing. The pump inlet protection mechanism can be formed of ahydrophobic material to prevent fluid from entering the pump.

In some embodiments, the upper surface of the electronics unit caninclude one or more indicators 266 for indicating a condition of thepump and/or level of pressure within the dressing. The indicators can besmall LED lights or other light source that are visible through thedressing material or through holes in the dressing material above theindicators. The indicators can be green, yellow, red, orange, or anyother color. For example, there can be two lights, one green light andone orange light. The green light can indicate the device is workingproperly and the orange light can indicate that there is some issue withthe pump (e.g. dressing leak, saturation level of the dressing, and/orlow battery).

FIG. 2A-2C illustrates an embodiment of a pump and electronics unit 267.The electronics unit 267 can include a pump 272 and one or morebatteries 268 or other power source to power the pump 272 and otherelectronics. The pump can operate at about 27 volts or about 30 volts.The two batteries can allow for a more efficient voltage increase (6volts to 30 volts) than would be possible with a single battery.

The batteries 268 can be in electrical communication with a flexiblecircuit board 276. In some embodiments, one or more battery connectionsare connected to a surface of the flexible circuit board 276. In someembodiments, the flexible circuit board can have other electronicsincorporated within. For example, the flexible circuit board may havevarious sensors including, but not limited to, one or more pressuresensors, temperature sensors, optic sensors and/or cameras, and/orsaturation indicators.

In such embodiments, the components of the electronics unit 267 mayinclude a protective coating to protect the electronics from the fluidwithin the dressing. The coating can provide a means of fluid separationbetween the electronics unit 267 and the absorbent materials of thedressing. The coating can be a hydrophobic coating including, but notlimited to, a silicone coating or polyurethane coating. The pump inletcomponent can be used to protect the pump from fluid on the inlet andthe pump outlet mechanism can include a non-return valve that protectsfluid from entering the outlet as described in more detail withreference to PCT International Application No. PCT/EP2017/055225, filedMar. 6, 2017, titled WOUND TREATMENT APPARATUSES AND METHODS WITHNEGATIVE PRESSURE SOURCE INTEGRATED INTO WOUND DRESSING and PCTInternational Application No. PCT/EP2017/059883, filed Apr. 26, 2017,titled WOUND DRESSINGS AND METHODS OF USE WITH INTEGRATED NEGATIVEPRESSURE SOURCE HAVING A FLUID INGRESS INHIBITION COMPONENT, which ishereby incorporated by reference in its entirety.

The electronics unit 267 includes one or more slits, grooves or recesses271 in the unit between the pump and the two batteries. The slits,grooves or recesses 271 can allow for the electronics unit 267 to beflexible and conform to the shape of the wound. The unit 267 can havetwo parallel slits, grooves or recesses 271 forming three segments ofthe electronics unit 267. The slits, grooves or recesses 271 of the unit267 create hinge points or gaps that allows for flexibility of theelectronics unit at that hinge point. The pump exhaust vents 264, switch265, and indicator 266 are shown on the top surface surrounded by theelectronics unit 267. As illustrated, one embodiment of the electronicsunit 267 has two hinge points to separate the unit into three regions orpanels, for example one to contain one battery, one to contain the pump,and one to contain another battery. In some embodiments, the slits,grooves or recesses may extend parallel with a longitudinal axis of thedressing that extends along the length of the dressing through theelectronics area of the dressing through the absorbent area of thedressing.

FIG. 3 illustrates an embodiment of a wound dressing incorporating anelectronics unit 367 within the dressing. In some embodiments, the wounddressing can include a wound contact layer 304. The dressing can alsoinclude a transmission layer 305 which may be made of a 3D materialabove the wound contact layer. In some embodiments, the electronics subassembly or electronics unit 367 can be embedded in an aperture or holein an absorbent pad 302 towards one end of the dressing, as depicted inFIG. 3 . As shown in the cross sectional view of the wound dressinglayers in FIG. 3 , the absorbent material 302 can be positioned on bothsides of the electronic components 367.

In some embodiments, the absorbent components in the absorbent area 360can be adjacent to or offset from the electronics unit 367 in theelectronics area 361 as illustrated in FIG. 3 . In some embodiments, theabsorbent components and electronics components can be overlapping butoffset. For example, a portion of the electronics area 361 can overlapthe absorbent area 360, for example overlapping the superabsorber layer,but the electronics area 361 is not completely over the absorbent area360. Therefore, a portion of the electronics area can be offset from theabsorbent area. The dressing layer and electronic components can beenclosed in a wound contact layer 304 positioned below the lower mostlayer and a cover layer (not shown) positioned above the absorbent layerand electronics. The wound contact layer and cover layer can be sealedat a perimeter enclosing the dressing components. In some embodiments,the cover layer can be in direct physical contact with the absorbentmaterial, and/or the electronics unit. In some embodiments, the coverlayer can be sealed to a portion of the electronics unit and/or casing,for example, in areas where holes or apertures are used to accommodatethe electronic components (e.g. a switch and/or exhaust).

FIGS. 4A-4C illustrate an embodiment of a wound dressing incorporatingan electronics unit resting in the absorbent layer. FIG. 4A illustratesa transmission layer 401. FIG. 4B illustrates an absorbent layer 402provided over the entire length of the transmission layer 401. Theabsorbent layer has one recess, cutout, or slot 407 in the portion ofthe absorbent layer 402 located in the electronics area. In FIG. 4B, thetransmission layer 401 is visible in the recess 407 of the absorbentlayer 402. The recess 407 is spaced and sized to fit the outer perimeterof the batteries and pump assembly of the electronics unit 404 (as shownin FIG. 4C) in one recess. In some embodiments, the recess in theabsorbent layer can include multiple recesses that are sized to fitindividual components of the electronics unit 404, for example, thebatteries and pump assembly as illustrated in embodiments described withreference to FIGS. 6, 7A-7C, and 8A-8F. FIG. 4C illustrates theelectronics unit 404 positioned within the recess 407 of the absorbentlayer 402. The dressing layers and components shown in FIG. 4C can beenclosed in a wound contact layer (not shown) positioned below thetransmission layer and a cover layer (not shown) positioned above theabsorbent layer and electronics. The wound contact layer and cover layercan be sealed at a perimeter enclosing the dressing components.

The wound dressing of FIGS. 5A-5B include an overlay layer 517comprising an additional layer of material positioned above the dressinglayers. In some embodiments, the additional layer can include a maskingor obscuring layer positioned above the dressing layers. The overlaylayer 517 can be positioned above the absorbent layer and electronicsand below the cover layer 513. In some embodiments, the overlay layer517 can include an aperture 540 over a portion of the electroniccomponents to allow the electronic components to be accessible fromabove the overlay layer. In some embodiments, the overlay layer 517 canbe an opaque material that does not allow the wound exudate or otherfluid to be visible from a top view of the wound dressing. In someembodiments, the overlay layer can be an absorbent or transmission layeras described herein. In some embodiments, the overlay layer can comprisea conformable material overlaying and overbordering the perimeter of thelower layers of transmission and absorbent materials so as to protectthe cover layer from being punctured by the lower layers when sealedover the dressing layers as described in more details below.

The wound dressing can include an electronics label or covering 541positioned over the aperture 540 in the overlay layer 517. In someembodiments, the label or covering 541 can be positioned under the coverlayer 513. In other embodiments, the cover layer 513 can be positionedbelow the label and can also have an aperture to allow the label orcovering 541 to communicate with the underlying electronic components.

FIG. 5B illustrate the wound dressing of FIG. 5A absorbing and retainingfluids while negative pressure is applied to the dressing.

FIGS. 5A-5B illustrate a label or covering 541 that can be positionedover and cover the electronics and an opening 540 in the overlay layer517

FIG. 6 illustrates an embodiment of wound dressing layers incorporatingthe electronic components within the wound dressing. FIG. 6 illustratesa wound dressing with a wound contact layer 610 configured to contactthe wound. A transmission layer or spacer layer 611 is provided over thewound contact layer 610. The transmission layer 611 can assist intransmitting and distributing negative pressure over the wound site.

A first layer of apertured absorbent material 651 can be provided overthe transmission layer 611. The first apertured absorbent layer 651 caninclude an aperture 629. In some embodiments, the aperture 629 can besized and shaped to fit the electronics unit 650 therein. The firstapertured absorbent layer 651 can be sized and shaped to the size of theelectronics area and does not extend into the absorbent area. In someembodiments, the apertures 629 can be shaped and sized to fit theindividual components of the electronics unit 650.

A second apertured absorbent layer 622 can be provided over the firstabsorbent layer 651. In some embodiments, the second absorbent layer 622include apertures 628. The second absorbent layer 622 can be sized andshaped to the size of the electronics area and absorbent area. In someembodiments, the apertures 628 can be shaped and sized to fit theindividual components of the electronics unit 650.

An electronics unit 650 can be positioned in the apertures 628 and 629of the first and second apertured absorbent material 651 and 622. Theelectronics unit 650 can include a pump 627, power source 626, and aprinted circuit board 681. In some embodiments, the pump 627 can includea pump inlet mechanism 1710 and an outlet mechanism 682. In someembodiments, the printed circuit board 681 can include electronicsincluding but not limited to a switch, sensors, and LEDs as describedherein. In some embodiments, the circuit board 681 can include one ormore hole to be positioned over one or more exhaust vents (not shown) inthe outlet mechanism 682 as described in more detail herein.

An overlay layer 617 can be provided over the electronics components 650and absorbent layer 622. In some embodiments, the overlay layer 617 canbe one or more layers of absorbent and/or transmission material asdescribed herein. In some embodiments, the overlay layer 617 cancomprise a conformable material overlaying and overbordering theperimeter of the lower layers of transmission and absorbent materials.In some embodiments, the overlay layer 617 can soften the edges of thewound dressing layers by decreasing the profile around the edges of thedressing layers. In some embodiments, the overlay layer 617 can beprovided to protect the cover layer from being punctured by the lowerlayers when positioned over the dressing layers as described in moredetails below. The overlay layer 617 can include an aperture 671 toallow access to at least a portion of the electronics unit 650positioned below.

A cover layer or backing layer 613 can be positioned over the overlaylayer 617. In some embodiments, when the overlay layer 617 is not used,the cover layer or backing layer 613 can be provided above absorbentlayers 622, and/or electronic components 650. The cover layer 613 canform a seal to the wound contact layer 610 at a perimeter regionenclosing the overlay layer 617, absorbent layers 622 and 651,electronic components 650, and the transmission layer 611. In someembodiments, the cover layer 613 can be a flexible sheet of materialthat forms and molds around the dressing components when they areapplied to the wound. In other embodiments, the cover layer 613 can be amaterial that is preformed or premolded to fit around the dressingcomponents. As used herein, the terms cover layer and backing layer canbe used interchangeably to refer to the layer of material in thedressing configured to cover the layers of the wound dressing.

In some embodiments, the cover layer or backing layer 613 can include anaperture 672. The aperture 672 can be positioned over at least a portionof the aperture 671 in the overlay layer 617 to allow access to at leasta portion of the electronics unit 650 positioned below. In someembodiments, the apertures 671 and 672 can allow access to the switchand/or venting holes of the pump exhaust.

A label 641 can be provided over the apertures 671 and 672 andpositioned over the exposed portion of the electronic components 650.The label can include the vent holes 642, indicator portions 644, and/orswitch cover 643. The indicator portions 644 can include holes ortransparent regions 644 for positioning over the one or more indicatorsor LEDs on the printed circuit board 681 below the label 641. The holesor transparent regions 644 can allow for the indicators or LEDs to bevisible through the label 641. In some embodiments, the switch cover 642can include a dome shaped cover positioned over the switch on theprinted circuit board 681. In some embodiments, the label 641 caninclude embossed features for the switch cover 642. In some embodiments,the embossed features of the switch cover 642 can prevent accidentalactivation or deactivation of the device. In some embodiments, theswitch or switch cover 642 can include a tab on the switch to preventaccidental activation or deactivation. The vent holes 642 of the labelcan allow exhaust from the pump outlet mechanism to pass through thelabel and exit the wound dressing to be exhausted to the atmosphere.

In some embodiments, the label can be positioned on top of the coverlayer or backing layer 613. The label can be sealed to the top surfaceof the cover layer. In other embodiments, the label 641 can bepositioned above the overlay layer 671 and below the cover layer orbacking layer 613. In such embodiments, the cover layer 613 can have oneor more apertures over one or more components of the label 641. Forexample, the cover layer 613 can have apertures over the vent holes 642,indicator portions 644, and/or switch cover 643.

FIGS. 7A-7C illustrates the individual layers of a wound dressing. FIG.7A illustrates a first apertured absorbent material 751 cut to fit thesize and shape of the electronics area.

FIG. 7B illustrates a second apertured absorbent layer 722 and atransmission layer 711. Both the second absorbent layer 722 andtransmission layer 711 can be a similar size and shape as shown in FIG.7B. The first apertured absorbent material 751 can be a smallerapertured absorbent material than the size of the second aperturedabsorbent layer 722.

FIG. 7C illustrates a transmission layer 711, a first aperturedabsorbent layer 751, a second apertured absorbent layer 722, and overlaylayer 717. As shown in FIG. 7C, the overlay layer 717 can have a largerperimeter size than the other layers of the dressing as to overhang theedges of the other layers of the wound dressing. In some embodiments,the overlay layer 717 can have a smaller thickness than the absorbentlayer 722 and transmission layer 711. In other embodiments, the overlaylayer 717 can have the same thickness or a greater thickness than theabsorbent layer 722 and transmission layer 711.

FIGS. 8A-8F illustrates the layers of the wound dressing incorporatingan electronics assembly within the dressing. As shown in FIG. 8A, atransmission layer 711 can be placed over a wound contact layer 710.FIG. 8B illustrates a bottom view of components of the wound dressing.FIG. 8B illustrates the bottom view of an electronic unit 750 embeddedwithin the apertures of the first apertured absorbent layer 751 and thesecond apertured absorbent layer 722. FIG. 8C illustrates a top view ofan electronics unit 750 embedded within the apertures of the firstapertured absorbent layer 751 (not shown) and the second aperturedabsorbent layer 722 placed over the transmission layer (not shown) andthe wound contact layer 710.

FIG. 8D illustrates the layers of the wound dressing device with theelectronics unit 750 embedded within the first apertured absorbent layer751 and the second apertured absorbent layer 722. The first aperturedabsorbent layer 751 and the second apertured absorbent layer 722 can beplaced over the transmission layer 711 and the wound contact layer 710.

FIG. 8E illustrates an overlay layer 717 positioned over the dressinglayers. The overlay layer 717 includes an opening or aperture 740positioned over a portion of the electronics unit 750. The aperture 740can allow for access to the switch, pump outlet components, and visualindicators on the top surface of the electronics unit 750.

A label or covering 741 can be positioned over and cover the electronicsand an opening 740 in the overlay layer 717 as shown in FIG. 8F. FIG. 8Fshows a cover layer 713 covering the overlay layer 717 and electronicscovering 741 and underlying dressing and electronics components. Thecover layer 713 can seal to the wound contact layer 710 (shown in FIG.8C-8E) at a perimeter region of the wound contact layer 710. In someembodiments, the label or electronics covering 741 can be positionedover the cover layer 713. In some embodiments, the cover layer 713 canseal over the electronics covering 741. In some embodiments, theelectronics covering 741 can include a switch cover 743, one or morevisual indicators 744, and/or pump outlet vent(s) 742 as shown in FIG.8F. In some embodiments, the cover layer 713 can include one or moreholes in the cover layer 713 positioned over the switch and/or pumpoutlet vent(s). In some embodiments, the cover layer 713 can include asingle hole that is positioned over the switch cover 743, visualindicators 744, and/or pump outlet vent(s) 742 in the covering or label741 as shown in FIG. 8F. In some embodiments, the label can includeembossed features for the switch cover 743. In some embodiments, theembossed features of the switch cover 743 can prevent accidentalactivation or deactivation of the device. In some embodiments, theswitch or switch cover 743 can include a tab on the switch to preventaccidental activation or deactivation.

The visual indicators 744 can provide an indication of operation of thenegative pressure source and/or an indication of the level of negativepressure that is applied to the wound. In some embodiments, the visualindicators can include one or more light sources or LEDs. In someembodiments, the visual indicator light sources an illuminate toindicate a condition or change of condition. In some embodiments, thelight source can illuminate in a particular sequence and/or color thatindicates a condition. For example, in some embodiments, the lightsource can flash to notify the user that the device is operatingproperly. In some embodiments, the light source can automatically flashperiodically and/or the light source can be activated by the switch orother button to light up and indicate a condition.

In some embodiments, the switch can be pressed and/or held down to powerthe dressing and electronics on and off. In some embodiments, once theswitch is activated and the pump and associated colored LED, forexample, green colored LED, can be used to conformed the dressing andintegrated negative pressure source is operational. In some embodiments,during operation of the pump and dressing, the pump and dressing canenter the fault state indicated by a colored LED, for example, orangecolored LED.

The electronics components can be incorporated in the dressing. Forexample, the dressing components can be assembled to form one integratednegative pressure dressing to be positioned over a wound. The followingassembly description describes an embodiment of the assembly of anintegrated wound dressing. In some embodiments, some or all of theassembly process can be automated and/or any or all of the processes orprocedures can be done in any order.

A transmission layer can be positioned over the wound contact layer asshown in FIG. 8A. In some embodiments, the transmission layer can bepositioned with the larger pores facing upward or away from the wound.FIG. 8B illustrates a bottom view of some of the components of the wounddressing to illustrate the electronic components embedded within or fitinto the apertures of the large apertured pad or absorbent layer andsmall apertured pad or absorbent layer. In FIG. 8B, the electronicsassembly is positioned switch side down. FIG. 8C illustrates the topview of the electronics assembly within the apertured pads or absorbentmaterial placed directly on top of the transmission layer as shown inFIGS. 8C and 8D. The switch can be positioned on the top surface of theprinted circuit board as shown in FIGS. 8C and 8D.

The overlay layer 717 can be positioned over the apertured pads orabsorbent material with the aperture in the overlay layer positionedover the switch of the electronics assembly. In some embodiments, theedges and/or the outer perimeter of the overlay layer 717 can be adheredor secured to the top or upper surface of the wound contact layer 710. Atop film or cover layer can be placed over the overlay layer 717 asshown in FIG. 8F. In some embodiments, the perimeter of the cover layercan be secured to the top or upper surface of the wound contact layer710. In some embodiments, if the cover layer is positioned over theprinted circuit board, holes can be punctured in the top film at thelocation of the two exhaust ports. In other embodiments, the cover layeris provided with one or more apertures that are placed over the twoexhaust ports and/or other components of the electronics unit.

A label cover can be applied over the switch and/or other components ofthe electronics assembly that are exposed through the apertures of theoverlay layer 717 and the cover layer. The indicator portions caninclude transparent portions or LED windows aligned with the LED's onthe PCB when the label cover is applied. In some embodiments, the LEDwindows can include apertures in the label cover. In other embodiments,the LED windows can be transparent portions of the label cover. Theexhaust holes can also be aligned with apertures in the label cover.

FIG. 9 illustrates a cross sectional layout of the material layers ofthe wound dressing incorporating an electronics assembly within thedressing. The dressing 900 included multiple material layers and anelectronics assembly 950. The wound dressing 900 can include anelectronics area 961 including the electronics and an absorbent area ordressing area 960 that is intended to be applied to the wound asdescribed with reference to FIGS. 1A-1B. As described herein, the one ormore of the material layers can extend into both the electronics area961 and the dressing area 960. The dressing 900 can include a woundcontact layer 910, transmission layer 911, absorbent layers 922 and 951,an overlay layer, and a cover or backing layer 913 as illustrated inFIG. 9 . The absorbent layers 922 and 951 can include recesses orcutouts to receive the components of the electronics assembly 950 asdescribed herein. In some embodiments, the overlay layer 917 and/or thecover layer 913 can include a cut out over the switch and/or indicatorsof the electronics assembly 950. A label or covering 941 can bepositioned to cover at least a portion of the electronics assembly 950and any cutouts in the overlay layer 917 and/or the cover layer 913. Thelabel or covering 941 can be similar to the label or covering 741 asdescribed previously with reference to FIGS. 6 and 8F.

Before use, the dressing can include a delivery layer 945 adhered to thebottom surface of the wound contact layer. The delivery layer 945 cancover adhesive or apertures on the bottom surface of the wound contactlayer 910. In some embodiments, the delivery layer 945 can providedsupport for the dressing and can assist in sterile and appropriateplacement of the dressing over the wound and skin of the patient. Thedelivery layer 945 can include handles 946 that can be used by the userto separate the delivery layer 945 from the wound contact layer 910before applying the dressing 900 to a wound and skin of a patient.

Electronics Unit

The negative pressure wound therapy wound dressing described hereinutilizes an embedded electronic circuit assembly to generate thenegative pressure under the dressing. It can be important to protect theassembly from wound exudate or any other bodily fluid that would corrodethe electronics. In addition, it can be important to protect the patientfrom the electric or electronic components. The assembly incorporates apump which pulls air from the dressing to exhaust to the environment inorder to produce the required negative pressure differential. Therefore,the means of protection of the electronics cannot be a completeencapsulation or potting of the assembly. The protection must allowmovement of air from the dressing to the pump and exhausting thedressing to the environment. In addition, as a component of theelectronic assembly, it is essential to protect the pump from bodilyfluids. It can be helpful to provide a sealed electronics unit wherecomponents are protected from bodily fluids and environmental conditionsand also allow for communication with the wound dressing layers and theexternal environment. Additionally, it can be useful to allow theelectronic components integrated within the wound dressing toincorporate control circuitry and sensors to measure and determinenegative pressure applied to the wound.

In some embodiments, the electronics unit requiring protection from theenvironment of the wound dressing can be partially encapsulated, pottedor conformally coated. In some embodiments, the electronics unit caninclude a printed circuit board (PCB) 1081, the negative pressure source1072, and one or more power sources 1068 as shown in FIGS. 10A and 10B.In some embodiments, the entirety of the electronics unit except for thepump inlet and pump outlet can be coated in a potted silicon enclosure.In some embodiments, potting of electronic components can include aprocess of filling a complete electronic assembly with a solid orgelatinous compound for resistance to shock and vibration, exclusion ofmoisture, and/or exclusion of corrosive agents.

FIGS. 10A-10C illustrates the pump assembly system 1500 with the pumpinlet protection mechanism 1710 and pump outlet mechanism 1074 on thepump 1072. The pump assembly system 1500 can include cavities 1082 shownon the pump inlet protection mechanism 1710 and pump outlet mechanism1074. In some embodiments, the inlet protection and pump outletmechanisms can be adhered to the inlet and the outlet of the pump asdescribed herein. In some embodiments, the pump assembly system 1500 canbe assembled using an adhesive and allowed to cure prior toincorporating into the electronics assembly.

The pump inlet can be covered or fitted with a pump inlet protectionmechanism 1710. In some embodiments, the pump inlet protection 1710 canbe pushed onto the pump inlet as illustrated by the arrows in FIG. 11A.This can be a friction fit. The port of the pump inlet protection 1710that receives a portion of the pump inlet can be sized and shaped to bea complementary fit around the pump inlet. In some embodiments, the pumpinlet protection 1710 can be bonded onto the pump inlet using a siliconesealant or any other sealant or sealing technique. FIG. 11B illustratesthe pump inlet protection mechanism 1710 covering the pump inlet and thepump outlet mechanism 1074 covering the pump outlet. The pump outletmechanism 1074 can include vent holes 1084 to allow air exhausted fromthe pump to be exhausted from the pump outlet mechanism 1074. In someembodiments, the pump outlet mechanism 1074 can also include an exhaustvent hole 1084 in communication with a nonreturn valve and/or filtermembrane of the pump outlet mechanism.

FIGS. 11A-11B illustrate a pump inlet protection mechanism 1710 and pumpoutlet mechanism 1074 with cavities 1082. The pump assembly includingthe pump inlet protection mechanism 1710 and pump outlet mechanism 1074are placed over the surface of the printed circuit board 1081. When thepump assembly is in contact with the surface of the printed circuitboard 1081, the cavities 1082 can be positioned over sensors on theprinted circuit board 1081, for example, pressure sensors 1091 and 1092on the printed circuit board 1081 illustrated in FIG. 10B. As usedherein the terms pump exhaust mechanism and pump outlet mechanism can beused interchangeable to refer to the component or mechanism 1074positioned on the outlet of the pump.

The pressure sensors can be used on the printed circuit board to measureand monitor the pressure levels produced by the pump as well as thepressure differential between the atmospheric pressure and the pressureunderneath the wound dressing. FIG. 10B illustrates a first pressuresensor 1091 and a second pressure sensor 1092 on the printed circuitboard 1081. The first pressure sensor 1091 can be used to monitorpressure underneath the wound dressing, such as pressure in a fluid flowpath connecting the negative pressure source or pump 1072 and the wound,pressure at the wound, or pressure in the negative pressure source 1072.In some embodiments, the first pressure sensor 1091 can be in fluidcommunication with the cavity 1082 of the pump inlet protectionmechanism 1710 shown in FIGS. 11A-11B.

The second pressure sensor 1092 can be used to monitor pressure externalto the wound dressing. In some embodiments, the second pressure sensor1092 can be in fluid communication with the cavity 1082 of the pumpoutlet mechanism 1074 shown in FIGS. 11A-11B. The pressure external tothe wound dressing can be atmospheric pressure; however, the atmosphericpressure can vary depending on, for instance, an altitude of use orpressurized environment in which the TNP apparatus may be used.

The control circuitry of the PCB can control the supply of negativepressure by the negative pressure source 1072 according at least to acomparison between the pressure monitored by the first pressure sensor1091 and the pressure monitored by the second pressure sensor 1092. Insome embodiments, the control circuitry can vary the sampling rate atwhich pressures monitored by the first and second pressure sensors 1091and 1092 are sampled, such as based at least on an amount of energystored in the power source 1068 or whether the negative pressure source1072 is supplying negative pressure. The sampling rate can be varied,for instance, to increase an amount of power consumed (that is, byincreasing the sampling rate) or decrease an amount of power consumed(that is, by decreasing the sampling rate) by the control circuitry. Acontroller of the control circuitry can enter a sleep mode, which may bea mode during which the pressure monitored by the first and secondpressure sensors 1091 and 1092 is not sampled, and the controller canvary the sampling rate by entering the sleep mode. The sleep mode may bea mode from which the controller can be awoken via a hardware orsoftware interrupt. Embodiments of the wound dressings, wound treatmentapparatuses and methods described herein may also be used in combinationor in addition to those described in more detail with reference to PCTInternational Application No. PCT/EP2017/060464, filed May 3, 2017,titled NEGATIVE PRESSURE WOUND THERAPY DEVICE ACTIVATION AND CONTROL,which is hereby incorporated by reference in its entirety herein.

In some embodiments, a self-adhesive gasket 1711 and 1712 can be appliedto the pump inlet protection 1710 and pump exhaust mechanism 1074 thatseals the cavities 1082 of the pump inlet and pump exhaust aroundsensors on the printed circuit board 1081 and to seal around the exhaustmechanism vent holes and corresponding vent holes in the printed circuitboard as illustrated in FIG. 12 . In some embodiments, a pre-formedadhesive sheet can be used to form the sealing gaskets between thecavities 1082 of the pump inlet and pump exhaust mechanisms and sensorson the printed circuit board 1081 and between the exhaust mechanism ventholes and vent holes in the printed circuit board. In other embodiments,an adhesive can be used to seal the cavities 1082 of the pump inletprotection 1710 and pump exhaust mechanism 1074 around sensors on theprinted circuit board 1081 and to seal around the exhaust mechanism ventholes 1084 and corresponding vent holes in the printed circuit board.FIG. 10B illustrates an embodiment of adhesive applied to the printedcircuit board 1081 for adhering the pump inlet and pump exhaustmechanism to the printed circuit board 1081. In some embodiments, theelectronics unit can be embedded within layers of the dressing in theelectronics area 1361 as described previously. In some embodiments, thelayers of the dressing in the electronics area 1361 can include cutoutsor recesses into which the electronics unit can be placed.

The pump inlet component can be used to protect the pump from fluid onthe inlet and the pump outlet mechanism can include a non-return valvethat protects fluid from entering the outlet as described in more detailwith reference to PCT International Application No. PCT/EP2017/055225,filed Mar. 6, 2017, titled WOUND TREATMENT APPARATUSES AND METHODS WITHNEGATIVE PRESSURE SOURCE INTEGRATED INTO WOUND DRESSING and PCTInternational Application No. PCT/EP2017/059883, filed Apr. 26, 2017,titled WOUND DRESSINGS AND METHODS OF USE WITH INTEGRATED NEGATIVEPRESSURE SOURCE HAVING A FLUID INGRESS INHIBITION COMPONENT, which arehereby incorporated by reference in their entireties herein.

In some embodiments, the pump inlet protection mechanism 1710 can have acavity 1082 to surround the sensor or other feature on the printedcircuit board as shown in FIG. 13 . The pump inlet protection mechanismcan provide a large surface area available for vacuum to be drawn by theinlet of the pump. The pump inlet can fit within the recess 1083 in thepump inlet protection mechanism 1710 illustrated in FIG. 13 . The pumpinlet can be friction fit and/or form a complementary fit with therecess 1083 of the pump inlet protection mechanism as described herein.The pump inlet protection mechanism can have a rounded beveled shape orany other shape. The pump inlet protection mechanism can be formed froma porous material that allows for air or gas to pass through and cancomprise one or more porous polymer molded components. In someembodiments, the pump inlet protection mechanism can be hydrophobic. Insome embodiments, the pump inlet protection mechanism can have a poresize in the range of approximately 5 microns to approximately 40microns. In some embodiments, the pore size can be approximately 10microns. In some embodiments, the polymer can be one of hydrophobicpolyethylene or hydrophobic polypropylene. In some embodiments, the pumpinlet protection mechanism can be formed from a Porvair Vyon materialwith a pore size of 10 microns.

In some embodiments, the pump outlet mechanism can include a non-returnvalve as shown in FIG. 14 . In some embodiments, the pump outletmechanism can be bonded to the outlet of the pump using a sealant, forexample a silicone sealant. The non-return valve can be similar tonon-return valve described in PCT International Application No.PCT/EP2017/055225 incorporated by reference herein. As illustrated inFIG. 14 , the non-return valve 1410 can include a reed valve or looseleaf valve. In some embodiments, the non-return valve 1410 can be anysuitable mechanical one-way valve, such as, for example, a reed valve, aduckbill valve, a ball valve, or an umbrella valve, among others. Insome embodiments, the outlet or exhaust of the pump outlet mechanism caninclude an antimicrobial film and/or other filter membrane. In someembodiments, the antimicrobial film or membrane can filter the airexhausted from the pump to the atmosphere.

In some embodiments, the pressure sensor(s) positioned on the printedcircuit board aligned with the cavity of the pump inlet protectionmechanism can be used to measure a pressure at the inlet of the pump orthe inlet air flow. In some embodiments, the pressure sensor(s)positioned on the printed circuit board aligned with the cavity of thepump outlet mechanism can be used to measure a pressure at the outlet ofthe pump or the atmospheric air.

In some embodiments, software can be loaded onto the PCB. In someembodiments, the pump assembly 1500 including the pump inlet protectionmechanism and the pump outlet mechanism can be soldered, adhered, orotherwise attached to the PCB. When self-adhesive gaskets are usedbetween the pump assembly and PCB, the release liner can be pulled fromthe gaskets and the pump assembly can be pressed to the PCB to form aseal. In some embodiments, as illustrated in FIG. 10B, a thin bead ofgasket sealant can be applied around the two pressure sensors and theexhaust aperture in the PCB and the pump assembly can be pressed to thePCB to form a seal. In some embodiments, both self-adhesive gaskets andthe gasket sealant can be used. In some embodiments, the device utilizeseither the self-adhesive gaskets or the gasket sealant.

The batteries can be soldered or attached to the PBC ensuring theterminals are in the correct orientation as illustrated in FIG. 10A. Insome embodiments, a piece of foam or self-adhesive foam tape can beapplied to the face of one or more batteries.

In some embodiments, a metal clicker dome can be fixed at the switchposition on the PCB. In some embodiments, the clicker dome can be fixedor sealed to the PCB using an adhesive.

In some embodiment, a conformal coating can be applied to theelectronics sub assembly to provide electrical and mechanical isolationof the electronics from the patient, components of the wound dressing,and exudate in the wound dressing. In some embodiments, liberal siliconecoating can be applied to the electronics sub assembly. In someembodiments, the switch and LED's can remain uncoated. In someembodiments, the PCB edges can be coated. The coated assembly can becured and inspected to confirm there are no defects in the coating. Insome embodiments, more than one coating can be applied to the assemblyto confirm coating of all the appropriate components.

The assembled electronics components can be incorporated in the dressingas described above. For example, the dressing components can beassembled to form one integrated negative pressure dressing to bepositioned over a wound.

In some embodiments, the label and electronic components can be designedto provide mechanical and electrical isolation from the other areas ofthe dressing and from the patient. In some embodiments, the electricalisolation can be formed providing distance between the electroniccomponents and the label cover. In some embodiments, electricalisolation can be provided through the coating and/or encapsulating thepump or other electrical components with an electrical isolatingmaterial. The electrical isolating material can include, but is notlimited to, paint, foil, encapsulation with a conformable coating,and/or any other conductive material. In some embodiments, theelectrical components can be encapsulated or coated with titanium toelectrical isolate the electronic components. In some embodiments, thelabel can be formed from, coated with, or covered with the electricalisolating material. For example, the bottom surface of the label, incommunication with the electronic components can be coated or coveredwith the electrical isolating material. In some embodiments, the topand/or bottom of the electrical components and/or label can be coated orcovered with the electrical isolating material. The wound dressing withintegrated electronic components as described herein can bedefibrillation proof.

The wound dressing with embedded electronics can be any shape or size toaccommodate various types of wounds. For example, the wound dressingwith embedded electronics can have a rectangular, rounded rectangular,square, T shaped, or any other shape or design. In some embodiments, thewound dressings with embedded electronics described herein can berectangular or rounded rectangular shaped as illustrated with referenceto FIGS. 1A-2B. In other embodiments, the wound dressings with embeddedelectronics described herein can be a T shaped as illustrated withreference to FIGS. 4A-8F.

All of the features disclosed in this specification (including anyaccompanying exhibits, claims, abstract and drawings), and/or all of thesteps of any method or process so disclosed, may be combined in anycombination, except combinations where at least some of such featuresand/or steps are mutually exclusive. The disclosure is not restricted tothe details of any foregoing embodiments. The disclosure extends to anynovel one, or any novel combination, of the features disclosed in thisspecification (including any accompanying claims, abstract anddrawings), or to any novel one, or any novel combination, of the stepsof any method or process so disclosed.

Various modifications to the implementations described in thisdisclosure may be readily apparent to those skilled in the art, and thegeneric principles defined herein may be applied to otherimplementations without departing from the spirit or scope of thisdisclosure. Thus, the disclosure is not intended to be limited to theimplementations shown herein, but is to be accorded the widest scopeconsistent with the principles and features disclosed herein. Certainembodiments of the disclosure are encompassed in the claim set listedbelow or presented in the future.

What is claimed is:
 1. A wound dressing apparatus comprising: a woundcontact layer comprising a proximal wound-facing face and a distal face,wherein the proximal wound-facing face is configured to be positioned incontact with a wound; at least one absorbent layer over the woundcontact layer; and an electronics unit comprising: a negative pressuresource unit comprising a negative pressure source, a pump inletprotection mechanism, and a pump outlet or exhaust mechanism; aplurality of sensors positioned on a printed circuit board; wherein thepump inlet protection mechanism comprises a porous molded componentcomprising a first cavity configured to surround a first sensor of theplurality of sensors on the printed circuit board, and wherein theporous molded component further comprises a first recess spaced from thefirst cavity and configured to receive an inlet port of the negativepressure source; wherein the pump outlet or exhaust mechanism comprisesa second cavity configured to surround a second sensor of the pluralityof sensors on the printed circuit board, and the pump outlet or exhaustmechanism comprises a vent hole configured to allow air exhausted fromthe negative pressure source to be exhausted from the pump outlet orexhaust mechanism; and wherein the at least one absorbent layer isconfigured to be in fluid communication with the electronics unit; and acover layer configured to cover and form a seal over the wound contactlayer and the at least one absorbent layer.
 2. The wound dressingapparatus of claim 1, wherein a perimeter of the first cavity comprisesa first gasket configured to seal the perimeter of the first cavity inthe porous molded component to the printed circuit board around thefirst sensor of the plurality of sensors.
 3. The wound dressingapparatus of claim 1, wherein a perimeter of the second cavity comprisesa second gasket configured to seal the perimeter of the second cavity ofthe pump outlet or exhaust mechanism to the printed circuit board aroundthe second sensor of the plurality of sensors.
 4. The wound dressingapparatus of claim 1, wherein the printed circuit board comprises atleast one vent hole in the printed circuit board, wherein the vent holeof the pump outlet or exhaust mechanism is configured to be in fluidcommunication with the at least one vent hole of the printed circuitboard.
 5. The wound dressing apparatus of claim 3, wherein the secondgasket comprises an aperture configured to provide fluid communicationbetween a vent hole of the printed circuit board and the vent hole ofthe pump outlet or exhaust mechanism through the second gasket.
 6. Thewound dressing apparatus of claim 4, wherein the vent hole of the pumpoutlet or exhaust mechanism comprises an antibacterial membrane and/or anon-return valve.
 7. The wound dressing apparatus of claim 4, whereinthe cover layer comprises an aperture over the at least one vent hole inthe printed circuit board.
 8. The wound dressing apparatus of claim 1,wherein the electronics unit comprises one or more power sources.
 9. Thewound dressing apparatus of claim 1, wherein the at least one absorbentlayer comprises one or more recesses configured to receive theelectronics unit.
 10. The wound dressing apparatus of claim 9, furthercomprising a transmission layer comprising a proximal wound-facing faceand a distal face, the transmission layer positioned over the distalface of the wound contact layer.
 11. The wound dressing apparatus ofclaim 10, wherein the at least one absorbent layer comprises: a firstabsorbent layer comprising a proximal wound-facing face and a distalface, the first absorbent layer positioned on the distal face of thetransmission layer; and a second absorbent layer comprising a proximalwound-facing face and a distal face, the second absorbent layerpositioned on the distal face of the first absorbent layer.
 12. Thewound dressing apparatus of claim 11, further comprising an overlaylayer comprising a proximal wound-facing face and a distal face, theoverlay layer positioned over the distal face of the second absorbentlayer, wherein the overlay layer comprises a larger perimeter than aperimeter of the transmission layer and the first and second absorbentlayer.
 13. The wound dressing apparatus of claim 1, wherein theelectronics unit comprises a switch.
 14. The wound dressing apparatus ofclaim 1, wherein the electronics unit comprises a light or LEDindicator.
 15. The wound dressing apparatus of claim 1, wherein the pumpinlet protection mechanism and the pump outlet or exhaust mechanism areremovably attached to opposite ends of the negative pressure source. 16.The wound dressing apparatus of claim 1, wherein the pump inletprotection mechanism and the negative pressure source are coplanar. 17.The wound dressing apparatus of claim 1, wherein the pump outlet orexhaust mechanism and the negative pressure source are coplanar.
 18. Thewound dressing apparatus of claim 1, wherein an edge of the pump inletprotection mechanism abuts a first complementary edge of the negativepressure source forming a complementary fit between the pump inletprotection mechanism and the negative pressure source.
 19. The wounddressing apparatus of claim 1, wherein an edge of the pump outlet orexhaust mechanism abuts a second complementary edge of the negativepressure source forming a complementary fit between the pump outlet orexhaust mechanism and the negative pressure source.